1. Field of the Invention
The present invention relates to a method of ultra high sensitivity hydrogen detection in which, on the basis of slow multiply-charged ions from an ion source for efficiently generating multiply-charged ions such as an electron beam ion source (EBIS) or an electron cyclotron resonance ion source (ECRIS), damages caused on a target surface can be remarkably reduced and a quantitative analysis of hydrogen on a solid surface can be compactly realized with extremely high efficiency.
2. Description of the Related Art
The quantitative analysis of hydrogen on the solid surface and in the solid has been conventionally very difficult. As for the detection of hydrogen on the solid surface or in the solid, a method in which resonant nuclear reaction with nitrogen can be cited. In this method, the depth resolution estimated as the order of a few atom layers strongly depends on the energy resolution of an accelerator.
In the resonant nuclear reaction, nitrogen ions accelerated to a few MeV are necessitated and a phenomenon which acts as a probe is a nuclear reaction, so that the detection efficiency is very low and hence requires several hours, and further it is naturally required to provide an ion accelerator of middle size.
An outlined arrangement provided for the conventional method of hydrogen detection is shown in FIG. 1. In FIG. 1, 1 denotes a negative ion source, ions extracted from the negative ion source are accelerated and charge-stripped by a tandem accelerator 2 and charge-state-analyzed by an analyzing magnet 3 and then transported to a target 5 which is set in an experimental vacuum chamber 4, where .gamma.-rays emitted from the target 5 are detected by a .gamma.-ray detector 6.
As mentioned above, the conventional method of surface hydrogen detection is large-scaled and has low detection efficiency and further has a serious defect in the sense that the target surface is strongly damaged by the collision of the probe ions.
In addition, atoms on the solid surface which are heavier than hydrogen, for instance, Li-atoms, have been conventionally detected through Auger electron spectroscopy which has a particularly high sensitivity in the vicinity of the solid surface. However, hydrogen atoms don't emit Auger electrons and hence form a blind spot of the conventional method of surface atom detection.